Thermalization in Krylov basis

Abstract We study thermalization in closed non-integrable quantum systems using the Krylov basis. We demonstrate that for thermalization to occur, the matrix representation of typical local operators in the Krylov basis should exhibit a specific tridiagonal form with all other elements in the matrix...

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Main Authors: Mohsen Alishahiha, Mohammad Javad Vasli
Format: Article
Language:English
Published: SpringerOpen 2025-01-01
Series:European Physical Journal C: Particles and Fields
Online Access:https://doi.org/10.1140/epjc/s10052-025-13757-2
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author Mohsen Alishahiha
Mohammad Javad Vasli
author_facet Mohsen Alishahiha
Mohammad Javad Vasli
author_sort Mohsen Alishahiha
collection DOAJ
description Abstract We study thermalization in closed non-integrable quantum systems using the Krylov basis. We demonstrate that for thermalization to occur, the matrix representation of typical local operators in the Krylov basis should exhibit a specific tridiagonal form with all other elements in the matrix being exponentially small, reminiscent of the eigenstate thermalization hypothesis. Within this framework, we propose that the nature of thermalization, whether weak or strong, can be examined by the infinite time average of the Krylov complexity. Moreover, we analyze the variance of Lanczos coefficients as another probe for the nature of thermalization. One observes that although the variance of Lanczos coefficients may capture certain features of thermalization, it is not as effective as the infinite time average of complexity.
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institution Kabale University
issn 1434-6052
language English
publishDate 2025-01-01
publisher SpringerOpen
record_format Article
series European Physical Journal C: Particles and Fields
spelling doaj-art-b8df8ad795fd4f3b9f5fceed8873f11e2025-01-26T12:49:33ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522025-01-0185111610.1140/epjc/s10052-025-13757-2Thermalization in Krylov basisMohsen Alishahiha0Mohammad Javad Vasli1School of Physics, Institute for Research in Fundamental Sciences (IPM)School of Physics, Institute for Research in Fundamental Sciences (IPM)Abstract We study thermalization in closed non-integrable quantum systems using the Krylov basis. We demonstrate that for thermalization to occur, the matrix representation of typical local operators in the Krylov basis should exhibit a specific tridiagonal form with all other elements in the matrix being exponentially small, reminiscent of the eigenstate thermalization hypothesis. Within this framework, we propose that the nature of thermalization, whether weak or strong, can be examined by the infinite time average of the Krylov complexity. Moreover, we analyze the variance of Lanczos coefficients as another probe for the nature of thermalization. One observes that although the variance of Lanczos coefficients may capture certain features of thermalization, it is not as effective as the infinite time average of complexity.https://doi.org/10.1140/epjc/s10052-025-13757-2
spellingShingle Mohsen Alishahiha
Mohammad Javad Vasli
Thermalization in Krylov basis
European Physical Journal C: Particles and Fields
title Thermalization in Krylov basis
title_full Thermalization in Krylov basis
title_fullStr Thermalization in Krylov basis
title_full_unstemmed Thermalization in Krylov basis
title_short Thermalization in Krylov basis
title_sort thermalization in krylov basis
url https://doi.org/10.1140/epjc/s10052-025-13757-2
work_keys_str_mv AT mohsenalishahiha thermalizationinkrylovbasis
AT mohammadjavadvasli thermalizationinkrylovbasis